From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58663) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cj3Qo-0004aV-KG for qemu-devel@nongnu.org; Wed, 01 Mar 2017 07:32:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cj3Qk-0002oR-PG for qemu-devel@nongnu.org; Wed, 01 Mar 2017 07:32:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33692) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cj3Qk-0002nO-Iy for qemu-devel@nongnu.org; Wed, 01 Mar 2017 07:32:30 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8F2DB8047F for ; Wed, 1 Mar 2017 12:32:30 +0000 (UTC) From: "Daniel P. Berrange" Date: Wed, 1 Mar 2017 12:32:23 +0000 Message-Id: <20170301123223.12489-1-berrange@redhat.com> Subject: [Qemu-devel] [PATCH] migration: allow clearing migration string parameters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Markus Armbruster , Eric Blake , Juan Quintela , "Dr. David Alan Gilbert" , "Daniel P. Berrange" Some of the migration parameters are strings, which default to NULL, eg tls_hostname and tls_creds. The mgmt app will set the tls_creds parameter on both source and target QEMU instances, in order to trigger use of TLS for migration. After performing a TLS encrypted migration though, migration might be used for other reasons - for example, to save the QEMU state to a file. We need TLS turned off when doing this, but the migrate-set-parameters QAPI command does not provide any facility to clear/reset parameters to their default state. If you simply ommit the tls_creds parameter in migrate-set-parameters, then 'has_tls_creds' will be false and so no action will be taken. The only option that works with migrate-set-parameters is to treat "" on the wire as equivalent to requesting NULL. Failing that we would have to create a new 'migrate-reset-parameters' method to explicitly put a parameter back to its default value. Signed-off-by: Daniel P. Berrange --- CC'ing Eric & Markus since this is related to QAPI schema for migrate monitor commands migration/migration.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index c6ae69d..a5d41a9 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -872,11 +872,19 @@ void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp) } if (params->has_tls_creds) { g_free(s->parameters.tls_creds); - s->parameters.tls_creds = g_strdup(params->tls_creds); + if (*params->tls_creds == '\0') { + s->parameters.tls_creds = NULL; + } else { + s->parameters.tls_creds = g_strdup(params->tls_creds); + } } if (params->has_tls_hostname) { g_free(s->parameters.tls_hostname); - s->parameters.tls_hostname = g_strdup(params->tls_hostname); + if (*params->tls_hostnane == '\0') { + s->parameters.tls_hostnane = NULL; + } else { + s->parameters.tls_hostname = g_strdup(params->tls_hostname); + } } if (params->has_max_bandwidth) { s->parameters.max_bandwidth = params->max_bandwidth; -- 2.9.3